Blade de-icing is critical in WTG because there is a 20% to 50% increase in the loss production factor. Ice accretion on wind turbine blades causes:                Change in aerodynamic shape resulting in significantly reduced power production        Increased root loads and reduced blade life        Unbalanced mass on the rotor plane        Danger of ice throw from the blades        
In the case of melting ice, the principal characteristic is the surface-ice interface temperature which has to be above freezing. When melting occurs at the blade surface-ice interface, chunks of ice fall off as a result of wind and gravity forces.
The amount of heat and the time required to melt the ice depends on numerous factors. These include the thickness of the ice layer, the loss of heat from the external surfaces of the blade, the external ambient temperature, and most importantly, the efficiency of the method for transferring the heat from the source to the frozen areas.